There are 2 other possible sources of the clunk which I suspect on my 237K 245.

The exhaust pipe under the rear axle has very little clearance. If the suspension is loose, the exhaust could easily contact the panhard rod or sway bar. With my car on jack stands today the exhaust was riding on the sway bar. This is not the normal position while driving but leads me to believe it could contact for example after backing out of the driveway.

My other concern is the new rear shocks I installed. I noticed today that the lower lug of the shock could slide inboard/outboard on the spacer inside the trailing arm. Makes me wonder if there was supposed to be a large diameter washer to prevent in from moving. I don't know if the shocks are preloaded enough from the weight of the vehicle & opposing force of the springs to prevent this.

Oh, one other item of suspicion. My drivline has about 5 to 10 degrees of rotation (by hand under the car) before I hear the differential gears engage & see the tires rotate. Is this amount of slop normal?


If someone has some thoughts on these I'm all ears.

Mike
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1988 245, 237K mi, 5 speed

Spent the last 18 months with this on our '83 245. Tons of time on the brickboard, tons of time under the car. Let me ask you this: Is this a low spectrum clunk, or a higher pitched clank? I know that sounds weird, but very significant. If the sound is low frequency and dull, it probably involves metal and rubber and is bushing related. If it is higher pitched it is most likely metal to metal. Lower pitched, go for bushings. There are lots of posts on the board about changing trailing arm bushings (TAB's). Tough job. Replace them with urethane, easier to install. Look for posts about the job from me, Art Benstein etc. Details on the tool you'll need if you go with stock bushings are from Art (http://www-ese.fnal.gov/People/wilcer/volvo_trailing_arm_bushing_tool.htm). Keep in mind that the front bushings in the rear arms rarely fail. However panhard rod bushings do. If you have a higher, metal to metal sound, start with u-joints. Keep in mind that you cannot find a failing u-joint with the shaft in unless the joint is literally about to come to pieces. If the joint is old, bound up, dry, sticky, it will not move much while the shaft is in the car. If you suspect joints, drop both ends of the shaft and check them. Again, if they are really bound up they can make the shaft bounce all over as it rotates which will cause noise. If they are really shot and loose you might be able to feel slop while they are in place, but better with them loose. Finally, high pitched clanks can result from metal to metal noise coming from rear wheel bearings, the differential, completely failed bushings causing bolts to bang against housings, or, as in my case, binding emergency brake shoes on one side of the axle. The e-brake cable was jammed and the brake would not always release. When I changed directions the shoes would shift, bind, then snap away from the inside of the disc hub making a sharp bang. Change direction again....same thing would happen. Other times the cable and brake would release fine after one bang and it would not happen for ages.

Check u-joints first, that's the easiest. A good pry bar and a strong light will help you inspect TAB's (unless they are shot--in which case you will see the sag as soon as you look at the mounting point!).

DS

IF it happens when you apply the accelerator AND when you apply the brakes, it could be torque rods
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jds

First I'd do what the others say to check the U-joints. You don't want to have one of these go out while the car is moving!BTDT

A more likely source is deteriorating TABs. There is nothing you can do to lube these. Eventually they will need replacing. I've done it but I wouldn't say it was easy. There is a lot of "how to" info on this forum. Try a search.

I've not had a differential make a clunk. When mine went bad in my old Chevvy, it just got louder gear whine.

If your foot is on the brake when you shift and hear the clunk. It's pretty safe bet that it is 'U' joints.

Put chocks in front and back of a tire , put the car in neutral ( not running) and slide under there. rotate the driveshaft ,and look at the 'U' joints, you should see the slop in them if they are bad.
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me

Seams to be a lot of clunking going on. I had a very loud clunk when I would set off in first or second. I thought it was a differential problem. It turned out to be a u joint. I had the u joints on the rear part of the drive shaft replaced but this was the front one. On advise from the members here I took off the front part of the drive shaft and took it in to my local specialist. He had it done while I waited. No more clunk. Get under the car and turn the drive shaft by hand. If you hear a clunking noise as you turn it back and forth you have bad u joints.
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Simon 1980 240 320k 19 years. 'White Lightning'